Exercising Air Footboard and Buffer for Air Footboard

ABSTRACT

Disclosed herein is an exercise step and an air-cushioning leg for the exercise step. The exercise step ( 1 ) includes a plate-shaped panel ( 10 ), and air-cushioning legs ( 30 ). Each of the air-cushioning legs is provided under the panel to support the panel, and absorbs a load applied to the panel by air cushioning effect. The exercise step has a high air cushioning effect, thus protecting a user&#39;s knees from injury, allowing the user to exercise in comfort and safety, and minimizing noise generated during a cushioning operation. Further, the exercise step prevents the panel from being deformed due to a load applied to the panel.

TECHNICAL FIELD

The present invention relates, in general to an exercise step and anair-cushioning leg for the exercise step and, more particularly, to anexercise step which is designed to have an excellent air cushioningeffect, thus protecting a user's knees from injury and allowing the userto exercise in comfort and safety, and which is designed to minimizenoise generated during a cushioning operation.

BACKGROUND ART

FIG. 1 is a perspective view of a conventional exercise step. As shownin the drawing, the conventional exercise step 100 includes arectangular panel 110, and four legs, 130. The legs 130 are provided atfour corners of the panel 110 under the panel 110, and are made ofelastic materials. A foot contact plate 120 is provided at a top surfaceof the panel 110. Actually, a user's feet are in contact with the footcontact plate 120 of the panel 110.

When one desires to exercise using the exercise step 100, the exercisestep 100 having such a construction is placed on a flat surface, thatis, a floor. Thereafter, a user repeatedly steps onto and off of thefoot contact plate 120 of the panel 110. Or, the user jumps on the footcontact plate 120. At this time, a load of the user is transmitted fromthe foot contact plate 120 and the panel 110 through the legs 130 to thesupport surface.

In this case, the legs 130 are elastically deformed to absorb a loadapplied to the panel 110, thus preventing a shock from being transmittedto the user's knees. That is, such an exercise step 100 prevents auser's knees from being injured, when the user repeatedly steps onto andoff of the foot contact plate 120 or jumps on the foot contact plate 120of the exercise step 100.

However, the conventional exercise step 100 has a problem that only thelegs 130 are made of a cushioning material, such as polyurethane, so acushioning capacity of the exercise step 100 is insufficient to preventa shock from being transmitted to a user's knees. Thus, the conventionalexercise step 100 does not sufficiently prevent a shock from beingtransmitted to a user's knees and allow the user to exercise safely andcomfortably.

Further, the conventional exercise step 100 has another problem thatonly the legs 130 have a cushioning capacity, so the foot contact plate120 and the panel 110 may be undesirably deformed when the exercise step100 is used for a lengthy period of time. The conventional exercise step100 has a further problem that the cushioning capacity of the legs 130is not controlled, so a different exercise step must be purchasedaccording to a user's weight.

DISCLOSURE OF THE INVENTION

Accordingly, the present invention has been made keeping in mind theabove problems occurring in the prior art, and an object of the presentinvention is to provide an exercise step with air-cushioning legs, whichhas an excellent air cushioning effect, thus protecting a user's kneesfrom injury and allowing the user to exercise in comfort and safety.

Another object of the present invention is to provide an exercise stepwith air-cushioning legs, which is designed to minimize noise generatedduring a cushioning operation and have an excellent cushioning effect.

A further object of the present invention is to provide an exercise stepwith air-cushioning legs, which is designed to prevent a panel frombeing undesirably deformed due to a user's load.

Still another object of the present invention is to provide an exercisestep with air-cushioning legs, which is designed to allow a user tocheck the number of steps and an exercise time while exercising.

In order to accomplish the above object, the present invention providesan exercise step, including a plate-shaped panel, and an air-cushioningleg provided under the panel to support the panel and absorbing a loadapplied to the panel by an air cushioning effect.

Further, in order to accomplish the above object, the present inventionprovides an air-cushioning leg for an exercise step, which is providedunder a support unit to absorb a load applied to the support unit, andwhich includes a main body having a double- or more-layered structureand an air control unit functioning to discharge a part of cushioningair from the main body to the outside, when a load is applied to thesupport unit.

In order to accomplish the above object, the present invention providesan air-cushioning leg for an exercise step, which is provided under asupport unit to absorb a load applied to the support unit, and whichincludes a main body having a plurality of tubular bulged parts havingdifferent capacities, the bulged parts arranged to form a layeredstructure, a closed base part coming into contact with a supportsurface, and an upper end partially opened to define an air passage, anair control unit seated in the open part of the upper end to control anamount of air which flows in and out the main body, and a cover membercovering the upper end of the main body in which the air control unit isseated.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a perspective view of a conventional exercise step;

FIG. 2 is a perspective view of an exercise step according to a primaryembodiment of the present invention;

FIG. 3 is an exploded perspective view of an air-cushioning leg shown inFIG. 2;

FIGS. 4 a to 4 c are a plan view, a side sectional view, and a bottomview of the air-cushioning leg shown in FIG. 3, respectively;

FIG. 5 a is a perspective view of an air control unit included in theair-cushioning leg of the primary embodiment of the present invention;

FIG. 5 b is a perspective view of an air control unit according to amodification of the primary embodiment of the present invention;

FIG. 6 is a perspective view of an exercise step according to a secondembodiment of the present invention;

FIG. 7 is a side sectional view showing a part of the exercise stepshown in FIG. 6, in which air-cushioning legs are removed from a panel;

FIGS. 8 a and 8 b are perspective views of one of the air-cushioninglegs included in the exercise step shown in FIG. 6, respectively;

FIG. 9 is a side sectional view of an air-cushioning leg according to athird embodiment of the present invention;

FIG. 10 is a side sectional view of an air-cushioning leg according to afourth embodiment of the present invention;

FIGS. 11 a and 11 b are plan views of air-cushioning legs according tofifth and sixth embodiments of the present invention, respectively;

FIG. 11 c is a bottom view of an air-cushioning leg according to aseventh embodiment of the present invention;

FIG. 12 is a perspective view of an exercise step according to an eighthembodiment of the present invention;

FIG. 13 is an exploded perspective view of one of air-cushioning legsincluded in the exercise step shown in FIG. 12; and

FIG. 14 is a perspective view of a sub-support leg included in theexercise step shown in FIG. 12.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference should now be made to the drawings, in which the samereference numerals are used throughout the different drawings todesignate the same or similar components.

FIG. 2 is a perspective view of an exercise step according to a primaryembodiment of the present invention. As shown in the drawing, anexercise step 1 according to the primary embodiment of the presentinvention includes a plate-shaped panel 10 and four air-cushioning legs30. The air-cushioning legs 30 are mounted to four corners of the panel10 under the panel 10.

A plurality of embossments 20 are formed on a top surface of the panel10. The embossments 20 prevent a user from slipping and falling on thepanel 10 during an exercise, in addition to functioning to massaging thesole of the user's foot. The embossments 20 may be separatelymanufactured and mounted to the top surface of the panel 10. Preferably,the embossments 20 are integrated with the panel 10 to form a singlestructure.

The panel 10 is a kind of laminated compressed wood, and is fabricatedby processing multi-layered sheets to which a synthetic resin is added,under high temperature and high pressure. When the panel 10 ismanufactured in this way, the panel 10 is somewhat hard, and hasexcellent elasticity and elastic strain, so the panel 10 is not easilydamaged or deformed.

A plurality of air-cushioning legs 30 are provided at four corners ofthe panel 10 under the panel 10 to absorb the load applied to the panel10. The air-cushioning legs 30 may be glued to the panel 10 under thepanel 10. Alternatively, the air-cushioning legs 30 may be screwed tothe panel 10 under the panel 10.

As shown in FIGS. 3 and 4 a to 4 c, each of the air-cushioning legs 30includes a main body 31, an air control unit 35, and a cover member 34.The main body 31 has a plurality of tubular bulged parts 31 b and 31 cwhich have different capacities and are arranged to form a layeredstructure. The main body 31 also has a base part 31 and an upper end 31d. The base part 31 is closed and comes into contact with a supportsurface. The upper end 31 d is partially opened to define an airpassage. The air control unit 35 is seated in an open part 33 of theupper end 31 d to control an amount of air which flows in and out themain body 31. The cover member 34 covers the upper end 31 d of the mainbody 31 in which the air control unit 35 is seated.

As shown in FIG. 4 a, the open part 33 of the upper end 31 d of the mainbody 31 includes a central opening 33 a, and a plurality of radial slits33 b. The central opening 33 a is formed at the center of the upper end31 d of the main body 31. The radial slits 33 b are provided along thecircumference of the upper end 31 d of the main body 31 at predeterminedintervals in such a way as to communicate with the central opening 33 a.A single radial slit may be formed, but it is preferable that aplurality of radial slits are formed, like the primary embodiment of thepresent invention.

That is, when a user steps onto or jumps on the panel 10, air isdischarged from the main body 31 through the central opening 33 a andthe radial slits 33 b to the outside. Subsequently, the bulged parts 31b and 31 c are compressed to absorb the load applied to the panel 10.

In the case where only the open part 33 is formed at the upper end 31 dof the main body 31, air excessively easily flows in and out the mainbody 31, so the load applied to the panel 10 is not effectivelyabsorbed. Thus, according to the present invention, the air control unit35, which is made of a porous material, such as a sponge, is seated inthe open part 33.

As shown in FIG. 5 a, the air control unit 35 includes a control body 35a, and a plurality of flanges 35 b. The control body 35 a is seated inthe central opening 33 a. The flanges 35 b outwardly extend from thecontrol body 35 a in a radial direction to be seated in the radial slits33 b.

When a user steps onto or jumps on the panel 10 after the air controlunit 35 is seated in the open part 33 of the upper end 31 d of the mainbody 31, air is discharged from the main body 31 through the controlbody 35 a seated in the central opening 33 a and the flanges 35 b seatedin the radial slits 33 b to the outside. Simultaneously, the bulgedparts 31 b and 31 c are compressed to absorb the load applied to thepanel 10. According to the present invention, since the air control unit35 is made of a porous material, noise is not generated even when airflows in and out the main body 31, thus allowing a user to exercise incomfort and safety.

Meanwhile, as shown in FIG. 5 b, an air control unit 35′ may have ashape different from the air control unit 35 of FIG. 5 a. That is, aplurality of through holes 35 c are provided in the control body 35 a toadditionally control the amount of air which flows in and out the mainbody 31. In this case, the shape and number of the through holes 35 cmay be changed.

The air control unit 35′ having a plurality of the through holes 35 c inthe control body 35 a as shown in FIG. 5 b, has a higher cushioningeffect in comparison with the air control unit 35 of FIG. 5 a. Thus, theair-cushioning leg 30 equipped with the air control unit 35 of FIG. 5 ais suitable for heavy adults, whereas the air-cushioning leg 30 equippedwith the air control unit 35′ of FIG. 5 b is suitable for light adultsand children.

As shown in FIG. 4 b, the bulged parts 31 b and 31 c comprise a firstbulged part 31 b and a second bulged part 31 c. The first bulged part 31b is provided adjacent to the base part 31 a of the main body 31. Thesecond bulged part 31 c is placed on the first bulged part 31 b to forma layered structure.

As shown in FIG. 4 b, it is preferable that the radius R1 of the firstbulged part 31 b is larger than the radius R2 of the second bulged part31 c to maintain a high cushioning effect and stability. Further, it ispreferable that junctions between the base part 31 a, the first andsecond bulged parts 31 c and 31 d, and the upper end 31 b areconstricted and inwardly rounded (see, “A”), thus allowing the main body31 to be smoothly compressed. Of course, the radius R1 of the firstbulged part 31 b, the radius R2 of the second bulged part 31 c, and thecapacities of the first and second bulged parts 31 b and 31 c must beproperly determined according to the size of the panel 10 and themagnitude of the load, but such variations are not described herein indetail.

As shown in FIG. 4 c, a plurality of foot parts 32 are projected from abottom surface of the base part 31 a of the main body 31, thuspreventing the base part 31 a of the main body 31 from being compresseddue to the load. According to the primary embodiment of the presentinvention, the foot parts 32 each have a rectangular block shape.However, the foot parts 32 may have a different shape without beinglimited to the rectangular block shape.

The use of the exercise step 1 constructed in this way will be describedin the following.

First, the exercise step 1 is placed on a flat surface, that is, afloor. Next, when a user repeatedly steps onto and off of the panel 10or jumps on the panel 10, the load applied to the panel 10 istransmitted to the support surface through the panel 10 and theair-cushioning legs 30.

At this time, the load applied to the panel 10 is absorbed by the panel10 to some extent, but the load is mostly absorbed by the air-cushioninglegs 30. That is, when the user compresses the panel 10, air isdischarged from the main body 31 through the control body 35 a seated inthe central opening 33 a and the flanges 35 b seated in the radial slits33 b to the outside. Simultaneously, the second bulged part 31 c isdownwardly compressed toward the first bulged part 31 b, thus absorbingthe load applied to the panel 10.

In this case, each of the air-cushioning legs 30 is provided with theair control unit 35 which is made of a porous material, thus preventingnoise from being generated even when air is discharged from the mainbody 31 to the outside, therefore allowing a user to enjoy exercising incomfort and safety.

Of course, as described above, the air-cushioning leg 30 equipped withthe air control unit 35 of FIG. 5 a is suitable for heavy adults,whereas the air-cushioning leg 30 equipped with the air control unit 35′of FIG. 5 b is suitable for light adults and children.

As such, the exercise step 1 equipped with the air-cushioning legs 30minimize noise generated during a cushioning operation, and has anexcellent cushioning effect, thus protecting a user's knees from injuryand allowing the user to exercise in comfort and safety.

As shown in FIG. 6, an exercise step 1 according to a second embodimentof the present invention includes a rectangular plate-shaped panel 10and a plurality of air-cushioning legs 30. The air-cushioning legs 30are mounted to four corners of the panel 10 under the panel 10. Arectangular foot contact plate 20 is provided on a top surface of thepanel 10. The foot contact plate 20 is made of an elastic material, suchas rubber, thus giving comfort to a user and having some cushioningeffect.

The panel 10 is a kind of laminated compressed wood, and is fabricatedby processing multi-layered sheets to which a synthetic resin is added,under high temperature and high pressure. Thus, the panel 10 is somewhathard, and has excellent elasticity and elastic strain, so the panel 10is not easily damaged or deformed.

A display unit 14 is provided at a predetermined portion of the panel10. The display unit 14 is connected to a control unit (not shown), anddisplays at least one of the number of steps and a time. Thus, a usermay set the number of steps and a time as desired when exercising.

As shown in FIG. 7, a plurality of bolts 10 a are provided at fourcorners of the panel 10 under the panel 10. Each air-cushioning leg 30is provided with a bolt receiving part 30 a so that the bolt 10 a istightened into the bolt receiving part 30 a (see, FIG. 8 a). That is, bytightening the bolts 10 a of the panel 10 into the bolt receiving parts30 a of the air-cushioning legs 30, the air-cushioning legs 30 areeasily mounted to the panel 10.

Although not shown in the drawings, the positions of the bolts 10 a andthe bolt receiving parts 30 a may be changed. That is, the bolts 10 amay be provided on the air-cushioning legs 30, while the bolt receivingparts 30 a may be provided on the bottom surface of the panel 10.

The air-cushioning legs 30 are provided under the panel 10 to supportit, and absorb the load applied to the panel 10. Each of theair-cushioning legs 30 includes a main body 40 and an air control unit50. The main body 40 is made of a material, such as polyurethane. Theair control unit 50 functions to discharge a part of cushioning air fromthe main body 40 to the outside, when the load is applied to the panel10.

The main body 40 may have a two-layered structure having two bulgedparts or a multi-layered structure having four or more bulged parts.However, according to the second embodiment of the present invention,the main body 40 has three bulged parts 40 a, 40 b, and 40 c, which arelayered in a vertical direction.

As shown in FIG. 8 b, the air control unit 50 according to the secondembodiment of the present invention includes a cover part 51 and acontrol part 52. The cover part 51 covers an open part of the main body40. Air flow holes 51 a and 51 b of different sizes are formed in thecover part 51. The control part 52 is rotatably mounted to the coverpart 51 to selectively open or close the air flow holes 51 a and 51 b.Preferably, the control part 52 is provided with a handle 52 a.

When a heavy adult uses the exercise step 1 of the present invention,the control part 52 is rotated to open a smaller air flow hole 51 a. Onthe contrary, when a light child uses the exercise step 1 of the presentinvention, the control part 52 is rotated to open a larger air flow hole51 b. Thus, the exercise step 1 of the present invention allows acushioning effect to be controlled according to the user's load.

The use of the exercise step 1 according to the second embodiment of thepresent invention will be described in the following.

First, the exercise step 1 is placed on a flat surface, that is, afloor. Next, when a user repeatedly steps onto and off of the footcontact plate 20 of the panel 10 or jumps at a fixed position on thefoot contact plate 20, the load applied to the panel 10 is transmittedto the support surface through the panel 10 and the air-cushioning legs30.

At this time, the load applied to the panel 10 is absorbed by the panel10 and the foot contact plate 20 to some extent, but the load is mostlyabsorbed by the air-cushioning legs 30. That is, the load is primarilyabsorbed when the bulged parts 40 a, 40 b, and 40 c of the main body 40are compressed. Secondarily, the load is absorbed when air is dischargedfrom the main body 40 through at least one of the air flow holes 51 aand 51 b to the outside.

When a heavy adult uses the exercise step 1, the control part 52 isrotated to open a smaller air flow hole 51 a. Meanwhile, when a lightchild uses the exercise step 1, the control part 52 is rotated to open alarger air flow hole 51 b. Thus, the exercise step 1 of the presentinvention allows an air-cushioning effect to be controlled according tothe user's load.

In the exercise step 1 according to the second embodiment of the presentinvention, a cushioning operation is effectively carried out by theair-cushioning legs 30, thus reducing a shock transmitted to the user'sknees, allowing the user to exercise in comfort and safety, andpreventing the panel 10 from being deformed by the load. Further, theuser may set and confirm a time and the number of steps during exercise.

Further, it is not necessary to provide the air control unit 50 shown inFIG. 8 b.

According to a third embodiment shown in FIG. 9, a main body 40′ of eachair-cushioning leg 30′ is designed such that two cover parts 42 and 43are provided at an open lower part of the main body 40′. In this case,the two cover parts 42 and 43 partially overlap with each other to forman overlapping part. An adjusting bolt 44 is tightened into theoverlapping part in such a way that the cover parts 42 and 43 are spacedapart from each other by a predetermined interval, thus controlling theamount of air which flows out of the main body 40′.

According to a fourth embodiment shown in FIG. 10, an air flow opening45 is provided at a side of a main body 40″, and a sliding door 46 ismounted to the air flow opening 45 to control an opening ratio of theair flow opening 45. The main bodies 40′ and 40″ according to the thirdand fourth embodiments also have foot parts 32 at the bottom surfaces ofthe main bodies 40′ and 40″.

Although not shown in the drawings, several through holes having apredetermined size may be provided in a side of the main body 40 toaccomplish a higher cushioning effect.

Further, according to a fifth embodiment shown in FIG. 11 a, a pluralityof air flow holes 151 a are bored through a cover part 151 which isprovided at the upper portion of the main body 140. When a control part152 is rotated, one or more air flow holes 151 a are opened.Alternatively, the main body of each air-cushioning leg may be designedto have a structure shown in FIG. 11 b. In FIG. 11 b, the referencenumerals designate components corresponding to those shown in FIG. 11 a.The components similar to those shown in FIG. 11 a are not describedherein in detail.

According to the fifth and sixth embodiments of FIGS. 11 a and 11 b, theair flow holes 151 a and 252 a are provided at the upper portions of themain bodies 140 and 240, respectively. However, air flow holes may beformed as shown in FIG. 11 c, to accomplish the same effect as the airflow holes 151 a and 252 a of FIGS. 11 a and 11 b. That is, according toa seventh embodiment of FIG. 11 e, a plurality of air flow holes 353 aare provided in the bottom surface of a main body 340, and a slidingdoor 346 is provided to selectively open or close the air flow holes 353a, thus controlling an opening ratio of the air flow holes 353 a.Further, foot parts 342 according to the seventh embodiment of thepresent invention are radially arranged on the bottom surface of themain body 340, differently from the above embodiments.

FIG. 12 shows an exercise step according to an eighth embodiment of thepresent invention. The exercise step 401 includes a panel 410. A footcontact plate 420 is provided on a top surface of the panel 410. Ahandle 470 is provided on the top surface of the panel 410 around thefoot contact plate 420. A plurality of air-cushioning legs 430 areprovided on four corners of the panel 410 under the panel 410.

As shown in FIG. 13, each of the air-cushioning legs 430 includes a body431 and an air cushioning tube 433. The body 431 is made of an elasticmaterial, such as thermoplastic polyurethane. The air cushioning tube433 is installed in the body 431. A recess 431 b is provided at a sideof the body 431. A plurality of air cushioning holes 431 a arevertically formed in the body 431 to accomplish a higher air cushioningeffect.

The air cushioning tube 433 is installed in the recess 431 b to absorb aload applied to the panel 410, in cooperation with the body 431. The aircushioning tube 433 may be fabricated in the form of a sealed tube withwhich air is filled. Further, the air cushioning tube 433 may be made oftransparent thermoplastic polyurethane, thus allowing people to see anadvertising member 432 which will be later described herein. Two or moreair cushioning tubes may be installed in the recess of the body,differently from the air-cushioning leg 430 shown in FIG. 13.

The advertising member 432 is provided between the inside wall of therecess 431 b and the air cushioning tube 433. The advertising member 432comprises a notice for advertising an article. However, theair-cushioning leg 430 may not be provided with the advertising member432.

Sub-support legs 460 are provided between the air-cushioning legs 430 toelastically absorb the load applied to the panel 410, in cooperationwith the air-cushioning legs 430 (see, FIG. 14). Each sub-support leg460 is made of an elastic material, such as thermoplastic polyurethane.Air cushioning holes 460 a are formed at each sub-support leg 460 toaccomplish a higher air cushioning effect.

Each sub-support leg 460 is shorter in length than each of theair-cushioning legs 430. Thus, when the exercise step 401 according tothe eighth embodiment of the present invention is placed on a flatsurface, the air-cushioning legs 430 are in contact with the supportsurface, but the sub-support legs 460 are spaced apart from the supportsurface.

When a strain of the panel 410 exceeds a reference level due to anexcessive load, the sub-support legs 460 come into contact with thesupport surface, thus preventing the strain of the panel 410 fromexceeding an elastic limit. Meanwhile, the air cushioning holes 460 aformed in each sub-support leg 460 function to increase the elasticstrain of the panel 10.

The exercise step 401 according to the eighth embodiment of the presentinvention is provided with the body 431, the air cushioning holes 431 aformed on the body 431, the air cushioning tube 433, the sub-supportlegs 460, and the air cushioning holes 460 a formed on the sub-supportlegs 460, thus enhancing an air cushioning effect, therefore preventinga shock from being transmitted to a user's knees, and allowing the userto exercise in comfort and safety, like the exercise steps according tothe above-mentioned embodiments.

According to the above-mentioned embodiments of the present invention,each air-cushioning leg 30 includes the main body 40 and the air controlunit 50. In this case, since the main body 40 has a three-layeredstructure and is made of thermoplastic polyurethane having a relativelyhigh elastic force, a sufficient cushioning effect is accomplished usingonly the main body 40 of each air-cushioning leg 30. However, when eachair-cushioning leg 30 includes the air control unit 50 as well as themain body 40, the cushioning effect of the exercise step 1 is maximized.

According to the above-mentioned embodiments, the panel 10 is made of alaminated compressed wood. However, the panel 10 may be made of woodhaving elasticity or other elastic materials. Further, the panel 10 hasa rectangular or circular shape, but the panel may have other shapes.

According to the above-mentioned embodiments, the foot contact plate 20is provided on the top surface of the panel 10. But, the panel 10 maynot be provided with the foot contact plate 20.

According to the above-mentioned embodiments, the air-cushioning legs 30are provided under the panel 10 to support the panel 10, and function toabsorb a load applied to the panel 10 during an exercise. However, theair-cushioning legs 30 are not necessarily provided at the panel 10.That is, the air-cushioning legs may be mounted to support legs (notshown) of a bed or a chair to achieve a cushioning effect. Since theair-cushioning legs mounted to the support legs have the sameconstruction as the air-cushioning legs 30 of the above-mentionedembodiments, the air-cushioning legs are not described in the following.

Although not shown in the drawings, in place of the air control unitaccording to the above-mentioned embodiments, an air inlet port and anair outlet port may be provided at both sides of the main body and adamper may be provided at the air outlet port to control an openingratio of the air outlet port, thus having the same effect as the aircontrol unit of the above-mentioned embodiments.

INDUSTRIAL APPLICABILITY

As described above, the present invention provides an exercise step,which has an excellent cushioning effect, thus preventing a shock frombeing transmitted to a user's knees and allowing the user to exercise incomfort and safety.

Further, the present invention provides an exercise step, which iscapable of minimizing noise generated during a cushioning operation, andhas an excellent cushioning effect. The exercise step of the presentinvention has a more excellent cushioning effect, in comparison with aconventional exercise step, thus preventing a panel from being deformedand thereby having a long life-span.

The present invention provides an exercise step, which is provided witha display unit, thus allowing a user to confirm the number of steps anda time during an exercise.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1-16. (canceled)
 17. An air-cushioning leg provided under a support unitto absorb a load applied to the support unit, said air-cushioning legcomprising: a main body having a two- or more-layered structure; and anair control unit functioning to discharge a part of cushioning air fromthe main body to an outside, when the load is applied to the supportunit.
 18. An air-cushioning leg provided under a support unit to absorba load applied to the support unit, said air-cushioning leg comprising:a main body, including: a plurality of tubular bulged parts havingdifferent capacities, said bulged parts being arranged to form a layeredstructure; a closed base part coming into contact with a supportsurface; and an upper end partially opened to define an air passage; anair control unit seated in the open part of the upper end to control anamount of air which flows in and out the main body; and a cover membercovering the upper end of the main body in which the air control unit isseated.